Various methods are known for flameproofing textile materials. These include treatments with chlorinated paraffins in combination with antimony oxide, treatment with tetrakis(hydroxymethyl)phosphonium chloride in combination with urea and/or N-methylol reagents, treatments with neutralized tetrakis(hydroxymethyl)phosphonium chloride in combination with ammonia, amides, or N-methylol compounds and, most recently, treatment with a combination of an oligomeric vinylphosphonate and an acrylic comonomer such as N-methylolacrylamide. The last-named system is decribed in U.S. Pat. No. 3,695,925. Each of these systems for attaining flame retardancy in textile materials has a characteristic set of attributes and deficiencies. A system approaching the optimum or ideal remains to be defined. In general, it is desirable to attain durable flame ratardancy in combination with durable-press or easy-care characteristics and with retention of low modulus (low stiffness), high strength, and high abrasion resistance.
It is an important object of the present invention to provide flame-retardant finishes that are effective on porous fibers, primarily cellulosic and other natural fibers, and that contribute various levels of flame retardancy to fibrous substrates with minimum increases in modulus (stiffness).
It is the further object to provide flame retardant textile finishes that may be employed to contribute various levels of flame retardancy to textile compositions together with high levels of retention of strength properties and abrasion resistance.
It is still another object of the present invention to provide the flame retarding textile finishes which are curable under very mild conditions and without the need for catalysis.
In the present invention, there is provided a process for flameproofing porous textile compositions with a combination of reagents that can be cured with a minimum of thermal energy to a durable textile finish that contributes flame retardancy and retains softness, strength, and abrasion resistance in the treated fabric.